AIS: results after surgery with posteromedial translation and all screw constructs ; Scoliose idiopathique de l'adolescent : résultats du traitement chirurgical par translation postéro-médiale au moyen de vis pédiculaires

Introduction: Scoliosis is a three-dimensional deformation of the spine. Severe, it can cause a deformation of the rib cage, including hypokyphosis. Three-dimensional spinal reconstructions from biplanar radiographs are validated. Posteromedial translation has been described with hybrid constructions. All screw constructions are more associated with direct derotation or in-situ bending techniques. According to the existing literature, they are associated with a flattening of the thoracic spine. Our objective was to evaluate the 3D radiological results, and in particular on the sagittal balance, after a surgical correction with posterior-medial translation using all screw constructions. Materials and Methods: 45 patients with AIS Lenke 1,2 and 6 requiring surgical correction were included prospectively. All performed low-dose biplane radiographs before and four months after the surgery, reconstructed semi-automatically. The main Cobb angle (Cp), kyphosis T1-T12 and T4-T12, L1-S1 lordosis, pelvic parameters, apical vertebral rotation, as well as the sagittal offset of the apical vertebra (SSAV), were analyzed. Results: Cp decreased from 60.6° (± 12.0°) preoperatively to 19.9° (± 9.4°) (p<0.0001), while T4-T12 kyphosis increased from 21.5° (± 15.1°) to 28.0° (± 9.9°) (p<0.0001). Posterior displacement (positive SSAV) of the apical vertebrae has been reported in 23 patients (51%). The SSAV and postoperative change of 3D kyphosis T4T12 were correlated (r= 0.70). Conclusion: Posteromedial translation via an all screw construct was effective in restoring thoracic kyphosis in the AIS. A posterior retreat of the apical vertebrae was correlated with a postoperative change in the kyphosis T4T12. ; Introduction : La scoliose idiopathique de l’adolescent (SIA) est une déformation tridimensionnelle du rachis apparaissant au moment du pic pubertaire. Sévère, elle peut entrainer une déformation de la cage thoracique, avec notamment une hypocyphose. Les reconstructions rachidiennes tridimensionnelles à partir de ...